1. Field of the Invention
This invention relates in general to the construction of electrical melting furnaces and in particular to a new and useful contact connection of the contact electrode of an arc or resistance melting furnace.
The contact electrodes in the direct current arc furnace (e.g. per DE-PS No. 31 06 741) are subject to wear earlier than the hearth liner. As relatively much labor is required to change the individual contact rods, the method has been adopted in the practice to change all contact rods jointly at corresponding intervals of time.
This changing is done preferably by lifting the bottom electrode in one piece out of the furnace tank and replacing it by a new one. For this operation it has heretofore been necessary to detach the current cables and the means for coolant supply from the bottom electrode.
The drawback of this procedure is that the current cables, due to their weight, are difficult to handle. For larger plants even erectio equipment is necessary. Moreover, the work is bothersome due to the radiant heat of the furnace floor.
To simplify and accelerate the work and to reduce the strain on the personnel, it has been proposed before to design the contact electrode so that the bottom electrode and current cable terminal can be separated from one another and hence the current cables and coolant supply lines can remain mounted.
The contact point constitutes the connection between the current cable terminal and the contact electrode. It must be suitable for conduction of the electric current and it must guide the coolant on into the bottom electrode.
This can be done in that the current cable terminal is secured on the furnace tank and has at its top side a contact point for connection to the contact electrode. Hence for removal of the contact electrode now the contact point between terminal and contact electrode must be separated. Current cables and coolant supply lines remain at the terminal, which itself is secured on the furnace tank.